What is CAC payback and why it’s so important for your SaaS?

CAC payback is a metric used in SaaS and eCommerce to determine how long it will take to recoup the costs of customer acquisition. Having an understanding of the CAC payback is critical for SaaS and e-commerce companies to structure a proper distribution, sales, and marketing strategy.

Understanding CAC payback

CAC (customer acquisition cost) payback describes the number of months that are required to recoup the money invested in acquiring new customers.

This metric is otherwise known as the breakeven point and clarifies how much capital the company needs to grow.

The shorter the payback period, the more quickly the company will become profitable.

CAC payback is a critical go-to-market metric for SaaS companies, with the most successful making it a board-level target.

To that end, continuous negotiation ensures the payback period is both predictable and reliable.

Calculating the CAC payback period

There are no formal or standardized means of calculating the CAC payback period.

One possible method, however, relies on the following three metrics:

  1. Customer acquisition cost (CAC).
  2. Average revenue per account (ARPA), and
  3. Gross margin percent.

To calculate the CAC payback period in months, divide the CAC by the ARPA multiplied by gross margin percent.

Higher numbers indicate the company is overspending on customer acquisition. Lower numbers indicate the reverse. 

Many consider a payback period of 12 months to be ideal, but a wiser strategy is to consider competitor benchmarks in conjunction with two additional metrics: 

Logo retention

The percentage of customers a business retains over a period of time.

For SaaS companies, this is expressed as a percentage of customers who renewed their accounts out of all those due for renewal over the same period.

Net dollar retention (NDR)

A measure of how much monthly or annual recurring revenue has increased or decreased over time.

NDR also considers factors like downgrades and negative churn.

CAC payback and lifetime value 

To determine how much should be spent on customer acquisition, businesses should calculate the CAC payback to lifetime value (LTV) ratio.

Lifetime value is the amount of revenue that, on average, a customer is expected to generate over their relationship with a company.

To calculate LTV, subtract the direct expenses per customer from the revenue per customer and then divide this number by one minus the customer retention rate.

To calculate CAC, divide the number of acquired customers by the direct marketing spend.

Calculating the CAC

LTV ratio is then a simple matter of dividing CAC by LTV.

CAC Payback case study

Consider an eCommerce shoe company that spends $5,000 on an AdWords campaign and in the process, acquires 500 new customers.

Average revenue per user is determined to be $45, while the cost of fulfilling each shoe order is $20.

Lastly, the shoe company retains 60% of its customers each year.

From this, we can see that the customer contribution margin is $45 – $20 = $25. 

LTV equals $25 divided by (1-60%) = $62.50.

CAC equals $5,000 divided by 500 = $10.

Thus, the LTV/CAC ratio is 62.5 divided by 10 which equals 6.25x. 

In this example, the ratio is reasonably high which means the shoe company is acquiring customers profitably.

Key takeaways

  • CAC payback is a metric used in SaaS and eCommerce that determines how long it will take to recoup the costs of customer acquisition.
  • A payback period of 12 months is considered to be ideal, but a wiser strategy is to consider competitor benchmarks in conjunction with metrics such as logo (customer) retention and net dollar retention.
  • To determine how much should be spent on customer acquisition, businesses should calculate the CAC payback to lifetime value (LTV) ratio.

Key Highlights

  • Definition and Importance: CAC Payback is a crucial metric in SaaS (Software as a Service) and e-commerce sectors. It calculates the time it takes for a company to recover the costs invested in acquiring new customers. Understanding this metric is vital for shaping effective distribution, sales, and marketing strategies.
  • Significance of Payback Period: The CAC Payback period represents the number of months needed to recoup customer acquisition costs. It’s also referred to as the breakeven point, shedding light on the capital required for growth. A shorter payback period indicates quicker profitability.
  • SaaS Emphasis: CAC Payback is especially significant for SaaS companies, with successful ones often setting it as a target at the board level. Continuous assessment and optimization ensure a predictable and reliable payback period.
  • Calculation Approach: While there’s no standardized method, one common way involves three metrics: Customer Acquisition Cost (CAC), Average Revenue per Account (ARPA), and Gross Margin Percent.
  • Calculation Formula: To calculate the CAC Payback period in months, divide CAC by (ARPA × Gross Margin Percent). Higher numbers indicate overspending on acquisition, while lower ones suggest efficiency.
  • Additional Metrics: To refine assessment, consider competitor benchmarks along with two more metrics:
    • Logo Retention: Percentage of customers retained over a specific period.
    • Net Dollar Retention (NDR): Measures changes in recurring revenue over time, considering factors like downgrades and negative churn.
  • LTV Ratio and CAC Payback: The CAC Payback to Lifetime Value (LTV) ratio is crucial. LTV is the expected revenue from a customer’s entire relationship with the company. Calculate LTV by subtracting direct expenses from revenue per customer, then dividing by (1 – customer retention rate). Divide the acquired customers by direct marketing spend to calculate CAC. The LTV/CAC ratio determines acquisition spending.
  • Case Study: For instance, an e-commerce shoe company spending $5,000 on an AdWords campaign acquires 500 customers. Average revenue per user is $45, with a cost of fulfilling each order at $20. Retention rate is 60%. LTV is $62.50, CAC is $10, and the LTV/CAC ratio is 6.25x. This high ratio indicates profitable customer acquisition.

Connected Financial Concepts

Circle of Competence

The circle of competence describes a person’s natural competence in an area that matches their skills and abilities. Beyond this imaginary circle are skills and abilities that a person is naturally less competent at. The concept was popularised by Warren Buffett, who argued that investors should only invest in companies they know and understand. However, the circle of competence applies to any topic and indeed any individual.

What is a Moat

Economic or market moats represent the long-term business defensibility. Or how long a business can retain its competitive advantage in the marketplace over the years. Warren Buffet who popularized the term “moat” referred to it as a share of mind, opposite to market share, as such it is the characteristic that all valuable brands have.

Buffet Indicator

The Buffet Indicator is a measure of the total value of all publicly-traded stocks in a country divided by that country’s GDP. It’s a measure and ratio to evaluate whether a market is undervalued or overvalued. It’s one of Warren Buffet’s favorite measures as a warning that financial markets might be overvalued and riskier.

Venture Capital

Venture capital is a form of investing skewed toward high-risk bets, that are likely to fail. Therefore venture capitalists look for higher returns. Indeed, venture capital is based on the power law, or the law for which a small number of bets will pay off big time for the larger numbers of low-return or investments that will go to zero. That is the whole premise of venture capital.

Foreign Direct Investment

Foreign direct investment occurs when an individual or business purchases an interest of 10% or more in a company that operates in a different country. According to the International Monetary Fund (IMF), this percentage implies that the investor can influence or participate in the management of an enterprise. When the interest is less than 10%, on the other hand, the IMF simply defines it as a security that is part of a stock portfolio. Foreign direct investment (FDI), therefore, involves the purchase of an interest in a company by an entity that is located in another country. 


Micro-investing is the process of investing small amounts of money regularly. The process of micro-investing involves small and sometimes irregular investments where the individual can set up recurring payments or invest a lump sum as cash becomes available.

Meme Investing

Meme stocks are securities that go viral online and attract the attention of the younger generation of retail investors. Meme investing, therefore, is a bottom-up, community-driven approach to investing that positions itself as the antonym to Wall Street investing. Also, meme investing often looks at attractive opportunities with lower liquidity that might be easier to overtake, thus enabling wide speculation, as “meme investors” often look for disproportionate short-term returns.

Retail Investing

Retail investing is the act of non-professional investors buying and selling securities for their own purposes. Retail investing has become popular with the rise of zero commissions digital platforms enabling anyone with small portfolio to trade.

Accredited Investor

Accredited investors are individuals or entities deemed sophisticated enough to purchase securities that are not bound by the laws that protect normal investors. These may encompass venture capital, angel investments, private equity funds, hedge funds, real estate investment funds, and specialty investment funds such as those related to cryptocurrency. Accredited investors, therefore, are individuals or entities permitted to invest in securities that are complex, opaque, loosely regulated, or otherwise unregistered with a financial authority.

Startup Valuation

Startup valuation describes a suite of methods used to value companies with little or no revenue. Therefore, startup valuation is the process of determining what a startup is worth. This value clarifies the company’s capacity to meet customer and investor expectations, achieve stated milestones, and use the new capital to grow.

Profit vs. Cash Flow

Profit is the total income that a company generates from its operations. This includes money from sales, investments, and other income sources. In contrast, cash flow is the money that flows in and out of a company. This distinction is critical to understand as a profitable company might be short of cash and have liquidity crises.


Double-entry accounting is the foundation of modern financial accounting. It’s based on the accounting equation, where assets equal liabilities plus equity. That is the fundamental unit to build financial statements (balance sheet, income statement, and cash flow statement). The basic concept of double-entry is that a single transaction, to be recorded, will hit two accounts.

Balance Sheet

The purpose of the balance sheet is to report how the resources to run the operations of the business were acquired. The Balance Sheet helps to assess the financial risk of a business and the simplest way to describe it is given by the accounting equation (assets = liability + equity).

Income Statement

The income statement, together with the balance sheet and the cash flow statement is among the key financial statements to understand how companies perform at fundamental level. The income statement shows the revenues and costs for a period and whether the company runs at profit or loss (also called P&L statement).

Cash Flow Statement

The cash flow statement is the third main financial statement, together with income statement and the balance sheet. It helps to assess the liquidity of an organization by showing the cash balances coming from operations, investing and financing. The cash flow statement can be prepared with two separate methods: direct or indirect.

Capital Structure

The capital structure shows how an organization financed its operations. Following the balance sheet structure, usually, assets of an organization can be built either by using equity or liability. Equity usually comprises endowment from shareholders and profit reserves. Where instead, liabilities can comprise either current (short-term debt) or non-current (long-term obligations).

Capital Expenditure

Capital expenditure or capital expense represents the money spent toward things that can be classified as fixed asset, with a longer term value. As such they will be recorded under non-current assets, on the balance sheet, and they will be amortized over the years. The reduced value on the balance sheet is expensed through the profit and loss.

Financial Statements

Financial statements help companies assess several aspects of the business, from profitability (income statement) to how assets are sourced (balance sheet), and cash inflows and outflows (cash flow statement). Financial statements are also mandatory to companies for tax purposes. They are also used by managers to assess the performance of the business.

Financial Modeling

Financial modeling involves the analysis of accounting, finance, and business data to predict future financial performance. Financial modeling is often used in valuation, which consists of estimating the value in dollar terms of a company based on several parameters. Some of the most common financial models comprise discounted cash flows, the M&A model, and the CCA model.

Business Valuation

Business valuations involve a formal analysis of the key operational aspects of a business. A business valuation is an analysis used to determine the economic value of a business or company unit. It’s important to note that valuations are one part science and one part art. Analysts use professional judgment to consider the financial performance of a business with respect to local, national, or global economic conditions. They will also consider the total value of assets and liabilities, in addition to patented or proprietary technology.

Financial Ratio



The Weighted Average Cost of Capital can also be defined as the cost of capital. That’s a rate – net of the weight of the equity and debt the company holds – that assesses how much it cost to that firm to get capital in the form of equity, debt or both. 

Financial Option

A financial option is a contract, defined as a derivative drawing its value on a set of underlying variables (perhaps the volatility of the stock underlying the option). It comprises two parties (option writer and option buyer). This contract offers the right of the option holder to purchase the underlying asset at an agreed price.

Read next:

Connected Video Lectures

Read next:

How To Read A Balance Sheet Like An Expert

Other business resources:

About The Author

Scroll to Top